hey guys
alright this is the story...b20 bored to 85mm..12.5 CP pistons, b16 head, block gaurd..... keeps running hot, yesterday filled w/ coolant, used the bleeder on thermostat housing, no air, ran HOT, TRIED AGAIN...ran w/ radiator cap off... raised rpms to get the air to bleed out... test drove, STILL,,... the thermostat is a oem B16 and installed properly, bleeder hole upwards(cant go in backwards) .. radiator was left open over 14months..(thats when I had it running before stock bottom end, not overheating at all) saw corrosion build up w/in radiator... replaced the radiator, used new coolant(other had crap in it) used bleeder, reved and filled w/ coolant,, idling fine. (oh fans running! have it constant) went off for another drive(thinking everythings cool) started to run hot again (not as high as the day before) I had the heater valve open during bleeding... somtimes its hot air,... sometimes its cold( think its airpockets) cant seem to figure it out... starting to think the thermostat is defective... bottom hose is cool.. top is blazing... what you guys think?.. thanks

 

If your bottom hose is hot as hell and your bottom is cool to the touch...and your engine is overheating...You definetly have a bad thermostat!! Or you have a very big air pocket..which i doubt cause you said you blead it several times...Before buying anything....remove your thermostat and drive it like that...if it stays cold cold...replace your thermostat..if it overheats you have more serious problems..hope this helps...

 

did u replace ur water bump before build?

 

yes, type r... I know water pumps leak at the weep hole.. but can the fins come loose from the shaft??.,..

 

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I'd pull the thermostat as mentioned above. Stick it in a pot of water on the stove and bring it to a boil, watch to see if it opens then season to taste.

I can't remember if the impeller is pinned to the shaft but if it's a press fit there is a small chance (a very small) that the impeller can spin on the shaft after it heats up and then locks back down on the shaft when it cools. However, you'd possibly see some marks on the block from the impeller.

 

sounds good man... thanks I figure its way rare for the waterpump being bad.. ill pull the thermo out not.. see what happens

 

sup guys
well boiled thermo today.. opened up fine...... this sux...diffenietly have a prob somewhere.....

 

Did you just put your motor back in? Does your heater work? Might be a long shot, but if your thermostat is good and fan is running constantly, then you might have a couple of your coolant hoses switched. Check to make sure all of your hoses are in the right places, I have seen this make a motor overheat.

Hope that helps.

 

well there is some coolant passages that are blocked off ( they are no use) got the upper hose to the head.. lower hose to thermo housing, heater nose from head to heater valve... intake manifold heater hose to heater core

 

aslo..I ran it at idle for like 20 min.. radiator cap off... found lower hose cool, it was full of air.. kept squeezinf it and felt the coolant slushing around.. finally got the air out and flowing right. caped it and drove.. still reading at 3/4 hot.. pulled over and checled.. lower hose cool again.. and full of air.. tried bleeing again.. got hotter....

 

I had the same exact problems as you. Do your radiator hoses feel tight to the touch also?

My radiator (stock) developed some pin holes. So I replaced it with a Fluidyne, I replaced the fan with a high performance slim fan. I replaced all the radiator hoses and the thermostat. But it still was pressurising too much.

I then tried some bars stop leak and it helped temorparily.

Essentially I was trying all of the easy things and wasting money because I did not want to hassle with the head gasket. I just replaced that today and viola, problem fixed. I can finally squeeze my radiator hoses again when the car is hot. :-)

 

cool.. going to do a compression and leak donw after thanksgiving.. think thatmight be the prob

 

is your motor tuned properly? you may be running lean which would cause it to run hot. i'd definately check your spark plugs or air fuel ratio to see because if your running lean for very long your motor is going to be fried

 

not perfectly. I know its not lean... have timming fully retarded at the moment... still on obd0 pr3 chipped... rc 310 injectors.. 50 psi fuel press.

 

You said your timing is fully retarded. This would cause a motor to get very hot. Use a timing light and set it to 16 degrees.

 

no.. retarding delays spark.. reduces detonation...., slower burn...

 

No actually if timing is retarded extremely it can increase the amount of heat the motor makes.

In some instances the mixture can still be burning when the exhaust valves are opening. If you have an EGT probe check out what your EGT's are doing under extremely retarded timing versus normal timing. In other words the compression stroke is over and on it's way back down the power stoke and already coming up the exhaust stroke and the mixture is still burning. This creates such intense exhaust that people running F.I. applications can have trouble regulating boost or will notice the glowing hot manifold. Your manifold could be doing the same thing actually.

Timing's main function is to fire the mixture at the proper rod angle so that the motor can make the most effortless horsepower. And your right advancing timing can increase motor heat as well. Ussually, this heat is advantageous though. It is heat created from a more efficient combustion. The only time timing becomes counterproductive is 1) pre-ignition from lack of octane support and 2) If the timing is so advanced it is firing against the pistons compression stroke.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxb20ed &raquo;</TD></TR><TR><TD CLASS="quote">well there is some coolant passages that are blocked off ( they are no use) got the upper hose to the head.. lower hose to thermo housing, heater nose from head to heater valve... intake manifold heater hose to heater core</TD></TR></TABLE>

i'm not sure what hose you blocked off coming from the head.. but the head needs coolant too..

*edit*
oh.. you are saying that you have those hoses hooked up....? but you have "some" blocked off that are no use.. it looked as if you were saying that all of those hoses you listed were blocked off


Modified by JL at 7:55 PM 11/25/2004

 

the head has the top hose to the radiator, on the side of the head goes straight to the heater control valve, the bottom radiator hose to the thermostat housing, my IACV has a coolant hose from the cross coolant tube, and the other hose from the thermostat housing, the other heater hose comes from the intake manifold(ITR) now on my thermostat housing there is like 2 5/8 fittings, and I think 1 1/2? fitting... them are blocked off, do not need them... other than that the head hoses are routed right.... at idle w/ the rad. cap off... I can get the coolant to flow all through.... bottom hose hot like top... and not overheating... as soon as I cap the radiator... drive it, starts to get hot.. and the bottom hose seems to get cold and pressurized like air is w/in.. this is why I think its my head gasket.. its just werid cause it running fine... not burning coolant.. and its been running for like 5 days.... head and block resurfaced....head checked thoroughly, no obvious coolant leaks... I doubt its drawing air into the cooling system somehwere and not leaking?? no cluse.. wends I am going to do a comprssion and leakdown... pressurize the coolant system..

 

hey anyone have the coolant hose routing? I need to know where the 5/8 hose from the ITR manifold goes? does it make a u-turn to the thermostat housing? think having it go str8 the the heater core will make coolant restrictions? thanks....

 

hey
okey I think I figured out whats might be going on..... I have a ITR intake manifold, on the left side there is a 5/8 fitting and a small other fitting for coolant.,... does that 5/8 do a u-turn to the fitting on the thermostat housing? I blocked off the coolant passages on the housing.... have a b20 in my 90 crx... I just need coolant hose routing if anyone has them... I could just get a manual but thought I would come here first.. thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxb20ed &raquo;</TD></TR><TR><TD CLASS="quote">hey
okey I think I figured out whats might be going on..... I have a ITR intake manifold, on the left side there is a 5/8 fitting and a small other fitting for coolant.,... does that 5/8 do a u-turn to the fitting on the thermostat housing? I blocked off the coolant passages on the housing.... have a b20 in my 90 crx... I just need coolant hose routing if anyone has them... I could just get a manual but thought I would come here first.. thanks
</TD></TR></TABLE>

I believe that the fitting coming off the manifold does a u-turn and goes to the thermo housing and then you should have a heater hose going to the thermo housing also.

 

yeah man... going to try it tomorrow.. this could prolly be why my thermostat doesnt ever open!... hot coolant str8 from the head is not getting the the thermostat...

 

hope it works!